Coal-auger.



PATENTED MAR. 17, 1908.

I M. MARTIN.

GOAL AUG APPLICATION FILED JUHE 19,1B07.

' INMENTOH NAT r -115w MA WIM.

' upon one edge thereor'a Alt'lIN, OF GILMORE, MARYLAND.

CDAL AUGER.

Specification of Letters Patent.

Patented March 1'7, 1908.

Application filed June 19, 1981?. Serial No. 379,696

To a ll whom it may concern:

Be it known that I, MATTHEW MARTIN, a citizen of the United States, and resident of Gilmorein the county of Allegany and State of Maryland, have invented an lm roves ment in Coal-Angers, of which the fol owing is a specification. a

My invention is an improvement in coalangers, and consists in certain novel constructions and combinations of. parts hereinafter described and claimed. I

Referring to the drawin s forming a part hereof, Figure l -is a centre; longitudinal section throughmj improvement. Fig. 2 is a section on the lme2 '2 of Fig. 1.

In the present embodiment of my. invention, the bit A comprises a ringc ihaving plurality of teeth a the shape shown in F1 1. The ring a is externally screw threads as at a at the opposite edge from the teeth, and a shoulder a is arran ed between the screw threaded por-- tion an the body portion of-the ring. tubular holder B is internally screw threaded at each end, as'at b, b one of said ends ongaging the threads of the ring and the other end being engaged by a section of pipe b the said pipe being supported in any suitable manner and connected with any suitable driving mechanism for rotating. the bit.

It will be noticed from inspection of Fig. 1 that the front edges of the teeth lire concave, and that the rear edges are conwcx, arr (l the teeth may be set or staggered with respect to each other, the depth of the set do enfding upon the hardness of the material to e openated u on. v

In t e operation of the device, since the bit is hollow, a core of coal is produced within the ring as the bit advances, and to break" up this core, a plate C is provided, the said plate being attached to the inner surface of I the holder B by means of the screws 0, and

one of the outer corners of the plate is turned atapproxirnately a right angle to the plate, as at c, and the edges of the said corner are sharpened to form cutting edges. The out:

' ting edge of theplate' acts upon the core,

breaking said core into small pieces, and asshoulder between the screw threaded. portion and the ring, a tubular holder for the ring, said holder being internally screw threaded at one end, said ring being threaded into the threaded end of the holder, means engaging the opposite end of the holder for rotating the cutter, and means within. the holder for breaking the core formed by the bit, said means comprising a plate dctachably connected with the inner-surface of the holder, one of the corners of said plate being turned outwardly at an angle to the plate and having itsedges formed lnto cutting edges for the purpose set forth.

2. A coal auger comprisin a ring havm one ,OFItS edges provided wit a plurality of teeth, the other edge of the nally tcrcw threaded and shoulder between the ring being exterprovided with a screw threaded portion and the ring, a tubular holder for the ring,

said holder engaging the threaded end of said ring, means engaging the opposite end of the holder for rotating the cutter, and means within the holder for breaking the core formed by the bit, said means C0111 risir f'a' plate detachably connected with t e inner surface of the holder, one of the corners of said. plate oein turned outwardly 'at an angle to the pate and having itsgl'edges formed into cutting edges for the purpose set forth. I f

3. A coal auger comprising a ring having one of its edges provided with aplurality of teeth, a tubular holder detachably connected with the other edge of the ring,-Ineans engaging the holder for rotating the cutter, and means within the holder for breaking the core formed by the bit, said means comprising a plate detachably connected with the inner surface oi the holder, one of the corners of said plate being turned outwardly at an angle to the plate and having its edges formed into cutting edges for the purpose set 1 means comprismia plate connected with the forth. i inner surace'o'f t e holder, one of the corners 10 4. A coal auger, comprisin a ring having i of said plate being turned outwardly at an one of its edges provided with a plurality of 3 angle to the plate. teeth, a tubular holder for the ring, means MATTHEW MARTIN. connected with the holder for rotating the i cutter, and means within the holder for breaking the core formed by the bit, said Witnesses .VVHJLIAM H. MARTIN,

JOHN J. MARTIN; 

